Lamp socket



R. w. JOHNSON Oct.' z, 1930.

LAMP SOCKET Filed Aug. 6,. 1928 nventoz M2M 5 is desired. Whiletheinvention may nous Patented Oct. 21, 1930 UNITED STATES@ PATENT NOFFICEo ROY w. JOHNSON, 'OF DETROIT, MicHIGAN,j Ass t OF DETROIT, iincmeAN,y ACORP V- lLAMP ,SOCKET` i Application` med AugustV 6,1928. serialNofzawse.

y Vinvention relatesito lampsoclkets fiori vehicle headlamps .and thelike, and more particularlyto a socket construction applicable to a lamp`where accurate positioning plied to a lamphaving means for adjustingthe focus thereof, it' is particularly advantageous in a headlamp oftheso-vcalled fixedi deiiection.

. for the base of the lamp bulb, but also radditional means "forsupporting the bulb in such away as tom close limits of tolerance.`

Another object is "to yprovide a lampy of i thefixed focus ornon-adjustablefocus typel wherein vthe interchangeablel lamp bulbs areall held in accurate relation to the focal point of the lamp within suchclose limitsof 'toler ance as to render the fixed focus type oflamppractical for Vehicle headlights.V i

These andother `objects are attainedfby the novel constructionhereinafter more fully described and illustrated in'the'accompany-llingV drawings", vwherein-f fi f y AFigure lA isa ,longitud'nal sectionthrough thesocket; f Y' j Y. t: ,y f Figure2 is anend yiew of`thesocket;

. Figure' 3" is a perspective view with portions cut-away toreveal'certain Afeatures of construction. Y

. 45 "The'drawings illustrate a ixedfociis bulbs `can be made whileHation between Vthe .actualfilament ,locationk of the invention isto.adapted. to,- bulb-frmly )within the socket member Vwithout Vpermittinge lateral;

'A secondobject is to provide a fsocket'ieon-lk struction havingnotjonly the usual retainerA yitself` o ainta'inthe filament in: y fixedrelation tothe axis fof "thelamp Withinl 1stein or -ieseiits the 'innersurface 'y of` the' emit v,the A,easy exchange o ,et constructionwherein the lamp and 2 the outer IGNOR To c. M. HALL LAMP COMPANY,ORMKIONOF ivucr'neANv ,Y

l is Vthe reflector of sleeve'of the socket which is permanentlyattached thereto by f suitable means such, for example,

the sleeve to theJ reflector as At the opposite end of the ing the metalof indicated at 3.

Vas clinchouter sleeve thereis preferably provided an seat ,y for a`coil spring 5. bulb retainer member inwardly turned annular flange 4forming a 6 represents the which'may be of a conventional typewandisillustrated' in the drawings as su`ch.f'].`h'usl the bulb retainery 6vf is tubular and has at the rearv end thereof the inturned annularlflange 7 for engaging the insulating core 8. This. core is providedwith the two apertures Qtherethrough for' slidably Contact portionsll atthe receiving the contact rods ,10. The

ends of the rods arefenlarged and form abutments for the contactlsprings rest against the shoulders 13 in the core at {thebase of therecessed portions 414:'. The

outerfend ofthe bulbjretainer has a plurality of 'J ,slotsl formed'4therein adaptedvto receive the ,proj ecting pins 16 17in the usual ofthe .lampbulbm .18 rep. lampl bulbiin its entirety, conmanner.

sisting of the bulb basel 17 aforementioned y and the .supported bulby19.y y, The filaments are lixedly within the bulb',

struction illustrated there are two filaments 20 and 2 1'spactedlvertically bulb. retainer in the :usual ingthe pins it has been found in16 toweiigage the J pressing fthe Vbulb axially and giving a slight-turningrmovement thereto. y y With bulb retainers of the typeillustrated commercial practice that o from ,each other.k

:Thelamp bulb maybe vinserted within the mannerY by causslots, that Vis,

the bulb is not rigidly held within the re- ,tions lduey to slightclearance tainer but has aslight movement in all direc` the fact thatthere` is always a between Vthe base 1"( vand `the f the lamp bulbs.`

The amount of displacement of the bulb filaments is sufficiently greatto materially affect the focus of the headlamp.

bly invention contemplates a construction adapted to prevent thisdeflection or, at least, to minimize the same to such an extent that itwill not throw the lamp enough out of focus to interfere with thesucelssful operation of a fixed focus type of lamp. My construe tionconsists in the arrangement of a sliding or telescoping sleeve 22surrounding the bulb retainer 6 and yieldably engaging the bulb 19 at apoint beyond the base thereo-f. This telescoping member 22 is thereforeprefer" ably flared at itsouter end as indicated at 23 in order to forma surface extending at substantially the same angle as the glass ofthebulb at the point of contact. The sleeve 22 is arranged between theouter sleeve 2fand the tubular bulb retainer 6. The sleeve has anannular inturned liange 24 engaging the spring 5.

In a fixed focus socket the bulb retainer 6 must be rigidly or fixedlymounted with respect to the refiector and in the present co-nstructionthis is accomplished by the use of a locking spring 25, the end 26 ofwhich passes through a slot 27 in the outer sleeve 2, a slot 28 in thetelescoping sleeve 22 and a slot 29 in the tubular bulb retainer G. Theslots 27 and 29 are of such size as to closely lit the portion 26 whichtherefore accurately positions the outer sleeve with reference to theinner bulb retainer. The slotv 2S in the telescoping sleeve is elongatedsuiiieiently to permit said telescoping sleeve to have sliding movementwithout having interference with the ortion 26.

l ith the construction as described above, the telescoping sleeve 22serves as an additional support for the lamp bulb, thus preventingwabbling of the bulb in any direction. It also maintains a resilientpressure upon the bulb in an axial direction, thus insuring that thepins 1.6 on the bulb base will be held in the most forward positionpermitted by the J slots of the bulb retainer. The sleeve, furthermore,holds the glass of the bulb in exact predetermined position with respectto the lamp socket and the lamp reflector. Thus by having allinterchangeable lamp bulbs so constructed the portion of the bulbengaging with the telescoping sleeve is in accurate predeterminedrelation to the filaments of the bulb, the improved socket constructionherein described isr also usefulv for maintaining the filamentsofinterchangeable lamp lbulbs in exact predetermined relation with thereflector. This relationship of the filaments to the base of the, glassportion of the bulb canbe maintained withinvery close limits and byinspecting each bulb to insure that it comes within the limitedtolerance set for this particular dimension it ispossible with myimproved socket construction to manufacture on a commercial scale afixed focus headlamp that will meet with the requirements for a safeheadlight.

It is to be understood that while my invention is particularly adaptedfor fixed focus lamps, it is not necessarily limited to this use for inits broader aspects the invention contemplates the provision of meansfor supporting the lamp bulb to prevent deflection thereof regardless ofwhether or not the lamp is providedv with means for adjusting the focus.

That claim as my invention is:

l. In a lamp, areflector, aI sleeve Xedly secured to1 saidi reflector,ya bulb retainer member fiXedly secured to 'said sleeve, a bulb carriedby the retainer' member, a second sleeve intermediate said first sleeveand retainer member and? having a bulb engaging portion, and means forresiliently urging the bulb engaging portion of said second sleeve intoengagement with saidV bulb.

2. ln a lamp, a reflector, a sleeve rigid with. the reflector, a bulbretainer member' within the sleeve and rigid therewith, a lamp bulbcarried by but movable relative to' said member, and a second.E sleevebetween said first mentionedv sleeve and member and movable vrelativethereto into engagementV with the bulb.

3. In a lamp, a reflector, a sleeve rigid with the reflector, a. bulbretainer member within the sleeve, a lamp bulb carried by the member, asecond sleeve between the first sleeve and member, and a connectionbetween saidV firs-t sleeve and member passing through the second sleevebut permitting it to move relative tothe other parts into engagementwith the bulb.

4. In a lamp, a reflector, a sleeve rigid with said reflector, a bulbretainer member within said sleeve, an element connecting said member tosaid' sleeve whereby said member is heldagainst movement relative tosaid sleeve, a. bulb carried by said member, a second sleeve slidablebetween said' member and first sleeve having a slot receiving saidelement and having a portion engaging with said. bulb, and means betweenportions of said. firs-t andA secondy sleeves holding the latter againstsaid bulb.

5. In av lamp, a reflector, a sleeve rigid with said reflector, abulbretainermember within said sleeve, an elementconnecting said memberto said sleeve whereby said member is held against movement relative tosaid sleeve, a bulb carried by the mem-ber, a second sleeveV slidablebetween said mem.- ber and first sleeve and having afiared portionengaging the bulb to position the same relative to the reflector, andyieldablemeans engagingthe second sleeve and holdingthe flared. portionthereof in engagement with. the bul 4 sleeve slidable between saidmember and first sleeve and engageable with the bulb to posli 6. In alamp, a refiector, e sleeve rigid with said reiector, a bulb retainermember within the sleeve, a bulb in the member, a second tion the samerelative to said reiector, and a connection between the member and rstsleeve including means extending the second sleeve permitting slidingmovement of said second sleeve but preventing movement of said memberrelative to said first sleeve.

In testimony whereof I affix my signature.

ROY W. JOH SON.

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